1. Field of the Invention
The present invention relates to a device for ablation of an artic valve on the human heart by a minimally invasive surgical operation.
2. Prior Art
The malfunctioning of an aortic valve results in cardiac insufficiency and hence in a situation that is potentially fatal for the patient. For repair of such a defect, artificial aortic valves have been developed which are implanted as a substitute for the damaged valve in complex and risky open-heart surgery (sternotomy). The operation becomes particularly difficult when there is strong calcareous degeneration on the natural valve because painstaking attention must be paid during removal in order to ensure that calcification particles will not enter the blood circulation and cause there thromboses at other sites in the body. It is common to fasten the replacement valvesxe2x80x94which are either mere engineering products or derived from porcine valvesxe2x80x94by suturing in the place of the removed valve.
There are numerous approaches in the development of methods simplifying this complex procedure of aortic-valve replacement in terms of both the surgical technique and the discomfort and strain for the patient, aiming at a minimally invasive technique of replacement of the aortic valve. In these approaches, the operation is performed via the femoral artery or even through the groin.
In view of the very restricted possibilities of access in the aortic arch, it is inevitable to adopt complex surgical strategies, firstly for explantation of the calcified aortic valve and secondly for implantation of an artificial valve in situ. Apart from all difficulties involved in the surgical operationxe2x80x94even though minimally invasive surgery is concerned that operates on advanced catheter technologyxe2x80x94a maximum of concentration and above all a steady hand is demanded from the surgeon, specifically as the individual steps of surgical handling are within the millimetre range and therebelow. With the minimally invasive operation being performed with a sustained natural function of the heart, it is moreover important to carry out the operation as quickly as possible in order to keep the strain on the cardiac system at a minimum, which means that an operation of this kind is performed under a certain pressure in terms of time.
A special aspect is the explantation or ablation of the calcified aortic valve that must be removed completely from the aorta as quickly as possible, without lesion of adjoining unaffected tissue regions, specifically as the explantation involves mostly the application of mechanically acute cutting tools. Furthermore, it is important to ensure that severed tissue fragments or calcification particles will be extracted from the blood stream without any residues so as to avoid the occurrence of embolism or thromboses.
The present invention is based on the task of solving the problem configuring a device for ablation of an aortic valve on the human heart by a minimally invasive surgical operation in such a way that the ablation of the calcified valve will be performed rapidly, without any residues and without excessive strain on the surrounding tissue material. It should become possible to collect severed calcification particles or freely movable tissue fragments completely or to extract them from the blood stream, respectively, by means of the device. In particular, the device should allow the removal of the valve while the natural cardiac action is sustained.
In accordance with the present invention a device for ablation of the aortic valve on the human heart by a minimally invasive surgical operation is configured to comprise a centering and fixing body adapted to be introduced inside the aorta, which body can be fixed, relative to the aorta, via at least one holding means. A drive shaft projecting through the centering and fixing body in a central position, at least partly, comprises a distal end on whose distal terminal section a cutting means is fixed for rotation. Moreover, on the centering and fixing body, on the proximal side relative to the cutting means, an aspirator means is provided through which the blood present in the aorta as well as calcification particles detached by the process of severing the calcified aortic valve may be extracted from the blood stream.
The centering and fixing body, which is preferably configured in the form of a hollow cylinder, comprises holding means that serve for fixing the centering and fixing body inside the aorta at an invariably defined location. The holding means are preferably designed as dilatable volume elements in the form of balloons or holding webs spreadable away from the cylinder, which are mounted on the outside cylinder wall. In this manner, it is possible that the centering and fixing body remains automatically stationary inside the aorta.
A particularly preferred embodiment provides for a fixedly implanted operating structure for positioning the centering and fixing body inside the aorta, which structure conforms to the inner wall of the aorta at a suitable locationxe2x80x94for example at a point adjacent to the aortic valve to be ablatedxe2x80x94in a stationary manner. The operating structure in its turn comprises a bayonet catch for a detachable fixed connection, into which the correspondingly shaped counter-contour of the bayonet catch can be inserted on the centering and fixing body. The operating structure, which will not be discussed here in further details, serves as a topologic fixing point for both the invention and further surgical tools, specifically catheter tools.
The inventive device for the selective ablation of the aortic valve will be explained in more details in the following, with reference to the figures described hereinbelow.